2010-03-12 11:36 PM
Just to test, I ran SQLIO
on a windows 2008 box (DL785) local disk (4x300G, RAID 10) vs a Netapp aggregate of 56 disks. Filer is running 126.96.36.199, this is a FC LUN. Aggregate is not really that loaded.
Surprisingly to me, the results show the C drive to be faster. I know there are various ways to tweak SQLIO but I still find this odd. Any suggestions would be appreciated:
SQLIO: 1 thread reading for 30 secs using 2KB IOs over 128KB stripes with 64 IOs per run:
Local C:\ [sqlio -dC]
Netapp F:\ [sqlio -dF]
SQLIO: 1 thread writing for 30 secs using 2KB IOs over 128KB stripes with 64 IOs per run:
Local C:\ [sqlio -kW -dC]
Netapp F:\ [sqlio -kW -dF]
2010-03-14 04:47 PM
What type of disk is the 56 disk aggregate, its RG size? What is you measure of "not really that loaded" ? Are disk queue lengths and latency response high in perfmon? Do you have performance advisor on this aggregate? Are storage latencies high?
2011-02-18 11:00 PM
We had an issue like this at the back end of 2009. It was caused by a 'rogue' HBA driver that windows had download from the server vender. Replaced with the NetApp drive and issue resolved.
Hope it helps